Network IP Addressing

[libertyos]

Hello.

I'm sure this is a stupid question- I have researched it on Google, thought about it and still can't find an answer.

How do you determine a company's IP address (internal) through nslookup or WHO IS? How does NAT affect this?

I'm sure there is a way to find the internal network addressing through the use of nslookup and WHOIS, however I just don't get it.

I would like to understand the process of determining what the internal IP addressing scheme is, how to find DMZ, firewall(s) etc....

I would appreaciate any help.

[Moonbat]

Well, there is a way, it's not definitely right, but usually works. First go to a site like http://www.arin.net/whois and look up an IP address of a company's site. I did a random IP and got this:


Comcast IP Services, L.L.C. CABLE-* (NET-7*-0-0-0-*)
7*.0.0.0 - 7*.255.255.255
Comcast IP Services, L.L.C. PITTSBURG-CDM-* (NET-7*-*44-0-0-*)
7*.*44.0.0 - 7*.*47.255.255

# ARIN WHOIS database, last updated 2007-06-*7 **:*0
# Enter ? for additional hints on searching ARIN's WHOIS database.

From what you can see, this Comcast company uses the IP ranges 7*.0.0.0-7*.255.255.255, and their division in Pittsburg uses the IP ranges 7*.*44.0.0-7*.*47.255.255. Somewhere in those IP ranges usually lies the IP for the company's intranet (internal network), and you can't always access it via port 80 (default HTTP port for accessing IPs and domains).

[Ezekiel]

I'm pretty much a networking noob, but if you mean their internal LAN addressing, I'm quite sure you're not gonna get that. Only their router and its LAN machines are privy to that information, and the router by definition is indistinguishable from a regular internet-connected computer. It uses NAT to let its clients use the net.